A medium-sized tech base with a depressing atmosphere. I almost lost it in a hard drive crash, so I decided to release it.

Story: You're the best of the best; a marine that saved the entire planet of Earth from Hell itself. A decade after saving the planet, the UAC was reformed, and they asked you to help them secure one of their research bases. At first, you were hesitant to aid the UAC, but they promised that they would not repeat the mistakes of their predecessors and would only research technology that would help destroy the demons, should they ever appear again. Hearing this, you agreed to help them, and so you find yourself on the UAC's Mars outpost.

Suddenly, it happened. You started hearing all sorts of screaming and gunfire over the radio, and then complete silence enveloped your surroundings. All of that happened in under twenty seconds. You know what's happening, and you know you have to stop it, but the mysterious force that invaded the base disabled all the doors, switches, and elevators. To make matters worse, all you have is a pistol.

Will you be able to defeat the demons once and for all? Gear up, marine.